That's a really, really tough decision, IMO.


If you decide on taking a P&S, the G11 or S90 would be good choices, IMO. Same sensor and both shoot RAW. So, it's similar to a dSLR lens choice, with the G11 getting you 35mm longer on the telephoto end (28-140 FFeq vs. 28-105mm FFeq for the S90), and the S90 having a wider aperture (f/2 vs. f/2.8 for the G11 - but, these are both variable zooms, and the G11 will have a slight aperture advantage at the longer end of the zoom ranges). If you're seeking portability, the S90 is hard to beat, but you'd give up the hotshoe and (non-TTL) viewfinder. The S90 could probably stay comfortably in your pocket all day, the G11 not so much. The 'control ring' on S90 seems like a really nice feature for someone used to manually setting aperture or shutter speed, or you can use it as a zoom ring. Between the two, I'd probably choose the S90 for optimal portability.


Of course, the 50D vs. P&S might be a harder choice than which P&S. Coming from a 50D, the slow AF and long shutter lag are going to be a challenge (as will theburst of only ~1 fps, if you shoot things that move quickly). ISO noise with a 4.6x crop sensor is going to be an issue compared to what you're used to. But the size/weight of the gear is a big trade off - would it really be50D plus lens, or would it be 50D plus lenses? My 'minimum' kit would be body (leave the grip home but take the extra battery), 17-55mm, 70-200mm, and an external flash.


One question (to which you may not know the answer) is, will there be a relatively secure location in the clinic where you can stow a camera bag while you're working? If so, and it were me, I'd be inclined to take the dSLR and two lenses (general purpose zoom and telephoto zoom), and bring them in the smallest backpack-style bag they'd fit into (something like a Lowepro Flipside 200 in red or blue). Take out a travel insurance policy with theft coverage for the trip.


Either way, have a great trip!


--John